Patent GB-551330-A (GB)
Title: Improvements in and relating to the manufacture of cyclammonium quaternary salts, of cyamine dyes, and of sensitized photographic emulsions
IPC: C09B23/04
Filed: 1941-08-16
Abstract: 551,330. Cyclammonium aryl quaternary salts, cyanine dyes, photographic sensitive emulsions. KODAK, Ltd. Aug. 16, 1941, No. 10452. Convention date, Aug. 21, 1940. Samples furnished. [Class 2 (iii)] [Also in Group XX] A cyclammonium aryl quaternary salt having an alkylmercapto group in the alpha or gamma position to the heterocyclic nitrogen atom is prepared by treating an N-aryl heterocyclic nitrogen base containing, in the alpha or gamma position, to the nitrogen atom, a doubly bound sulphur atom with an alkyl salt, for example an alkyl toluenesulphonate, an alkyl iodide or a dialkyl sulphate. In an example, 2 - - methylmercapto - 3 - phenylbenzthiazolium p-toluenesulphonate is prepared by heating together 3-phenyl-2-thiobenzthiazolone and methyl p-toluenesulphonate. The iodide or perchlorate may be produced by treating an aqueous solution of the compound with an aqueous solution of a water-soluble metal iodide or perchlorate. 2-Ethylmercapto-3- phenylbenzthiazolium p - toluenesulphonate and 2 - - methylmercapto - 3- -α or # - naphthylbenzthiazolium p-toluenesulphonate may be similarly prepared. 3-Phenyl-2-thiobenzthiazolone is prepared by adding phosphorus pentasulphide to a solution of 3-phenyl-2-benzthiazolone in m-xylene. NArylthia-cyanines are prepared by condensing the alkylmercapto substituted benzthiazolium salts with malonic acid in the presence of pyridine. 3 : 3<SP>1</SP>-Diphenylthiacyanine iodide may be prepared from 2-methylmercapto-3-phenylbenzthiazolium p-toluenesulphonate and malonic acid, the reaction mixture being poured into aqueous sodium iodide solution. 2<SP>1</SP>-, 4<SP>1</SP>-, and thia-cyanine dyes may be prepared by condensing the alkylmercapto substituted benzthiazolium aryl quaternary salts with cyclammonium quaternary salts containing a reactive methyl group, in the presence of an acid binding agent. 1<SP>1</SP>-Ethyl-3-phenylthia-2<SP>1</SP>- cyanine iodide is prepared by heating together 3-phenyl-2-thiobenzthiazolone and methyl ptoluenesulphonate, adding quinaldine ethiodide, absolute ethyl alcohol, and triethylamine, and refluxing. 1<SP>1</SP>- Ethyl -3 - phenylthia- 4<SP>1</SP> - cyanine iodide and 3-ethyl-3<SP>1</SP>-phenylthiacyanine iodide are similarly prepared using lepidine ethiodide and 2-methylbenzthiazole ethiodide respectively. Other acid binding agents are N- methylpiperidine, triethanolamine, and sodium or potassium carbonate. Photographic silver halide (e.g. silver chloride) emulsions may be sensitized with the dyes, which are either added to the finished washed emulsion or incorporated by bathing the plate or film. Samples have been furnished under Sect. 2 (5) of the Acts of (a) 2-methylmereapto-3- benzthiazolium iodide prepared by heating together 3-phenyl-2-thiobenzthiazolone and methyl iodide in a sealed tube and of (b) 2- methylmercapto - 1 - phenyl - # - naphthathiazolium p-toluenesulphonate prepared by heating together 1-phenyl-2-thio-#-naphthathiazolone and methyl p-toluenesulphonate. 1-Phenyl-2-thio-#-naphthathiazolone is prepared by heating together, in dry m-xylene, 2- nitrosinino - 1 - phenyl - # - naphthathiazoline and phosphorus pentasulphide. 2-Nitrosinino- 1-phenyl-#-naphthathiazoline is prepared by reacting 2 - imino -1 - phenyl-#-naphthathiazoline with glacial acetic acid and sodium nitrite. Specification 423,792 is referred to.